The object of this study was to evaluate the single dose toxicity of Iijintanggami-bang (IJTGMB), a polyherbal formula have been traditionally used as prevention or treatment agent for various digestive disorders including reflux esophagitis, in male and female mice. Aqueous extracts of IJTGMB (Yield = 8.45%) was administered to female and male ICR mice as an oral dose of 2,000, 1,000 and 500 mg/kg (body weight) according to the recommendation of Korea Food and Drug Administration (KFDA) Guidelines. Animals were monitored for the mortality and changes in body weight, clinical signs and gross observation during 14 days after dosing, upon necropsy; organ weight and histopathology of 12 principal organs were examined. As results, we could not find any mortality, clinical signs, and changesin the body and organ weight except for soft feces restricted to IJTGMB 2,000 mg/kg treated two male mice (2/5; 40%) at 1 day after administration. In addition, no IJTGMB-treatment related abnormal gross findings and changes in histopathology of principle organs were detected except for some sporadic accidental findings. The results obtained in this study suggest that the 50% lethal dose and approximate lethal dose of IJTGMB aqueous extracts in both female and male mice were considered as over 2,000 mg/kg, the limited highest dosage recommended by KFDA Guidelines.